In a standard pleated shade construction, a piece of material having a front side and a back side is pleated into a plurality of horizontal sections which stack one on top of the other when the shade is in its raised position. Alternate pleats face toward the front side or the rear side of the shade. Each section has at least one hole punched preferably through the transverse center thereof which holes are aligned when the shade is folded. Normally, there would be two or more aligned rows of holes formed in the shade sections. Lift cords passing through the aligned holes are utilized to control the raising and lowering of the shade and also control the folding of the pleat.
U.S. Pat. No. 4,974,656 discloses a pleated shade construction in which tabs are formed on the pleats on the rear of the shade. The tabs are formed by securing together the two sections of material forming each of the back projecting pleats along substantially the entire width of the material to form a tab of approximately five sixteenths to three eights of an inch projecting from the rear of each of such pleats. The sections may be secured together by welding, gluing, sewing or other suitable means. The lift cords are threaded through holes in the tabs which does not result in cords and holes being visible from the front of the shade. The rear projecting tabs permit two sections of pleated shade to be easily and invisibly spliced together at the tab. The rigidity of the pleats may be enhanced by providing a double-weld joint for the tab or by otherwise providing a multiple or continuous bond between the two fabric layers forming the tab. The joints used to form the tabs may be used as splice joints to secure together two pieces of shade material.
The pleated fabric disclosed in U.S. Pat. No. 4,974,656 and other prior art pleated shades typically exhibit a rectilinear or “hard” appearance, due in part to the material used to make the shade which is coated to hold the permanent creases and also due in part to the method of manufacture. Conventional methods of constructing the pleated material for a simple, single pleat type of shade involve either creasing the entire length of material at regular intervals, or creasing portions of material and creating tabs which may be joined together to form, or repair, a shade from more than a single piece of material. The “hard” appearance generally results because the creases or the tabs used to form the pleats are continuous along the entire width of the shade material and very straight, even sharp. Furthermore, there are some materials such as lace which are difficult to pleat because the weave is so open that there is not enough material to retain pleat retention coatings. There are also some fabrics that can discolor when ironed or coated to create or maintain pleats.
Consequently, there is a need for a pleated material which has a “softer,” more textured appearance than conventional pleated shades. There is also a need for a pleat that can be formed in lace and other fabrics without using ironing and coatings to create and maintain the pleats.